A controversial Australian doctor who backs euthanasia was allowed into the UK yesterday after an interview at Heathrow airport, his lawyer said.

Dr Philip Nitschke will give talks to supporters of his organisation, Exit International. He will also be promoting a testing kit designed to let would-be suicides know whether the barbiturates they have will be strong enough.

In 1996, Nitschke gave four patients lethal injections legally when euthanasia was permitted under Australian law in the Northern Territory. He has co-written a book called The Peaceful Pill eHandbook, which details eight ways that terminally ill people can kill themselves.